Vitamin C is a water-soluble vitamin that is important for human health as it helps to maintain the body’s resistance to various diseases. It functions as an antioxidant, which is a substance that gives electrons to free radicals and helps to stabilize free radicals, which protects cells from damage. Because vitamin C is easily oxidized, an analytical method is needed which measures vitamin C levels accurately and quickly. Analytical methods must be validated before being implemented to ensure the validity of the data generated. In this study, the validation of two vitamin C measurement methods were be compared: high-performance liquid chromatography (HPLC) and potentiometric titration. The results of the HPLC method showed that the linearity, accuracy, and precision met the validation requirements of the official methods of analysis (AOAC). The potentiometric titration method validation results showed that the accuracy met the AOAC requirements while the precision did not meet the AOAC requirements. Keywords: validation, HPLC, potentiometric titration, vitamin C